Overload release friction coupling



P 1951 M. K. BENSON OVERLOAD RELEASE FRICTION COUPLING Filed Nov. 21, 1946 IN VEN TOR. /7f/ /z 56/760 BY Patented Sept. 25, 1951 OVERLOAD RELEASE FRICTION COUPLING Merle K. Benson, Benton Harbor, Mich., assignor to T-M-K Corporation, Davenport, Iowa, a corporation of Iowa Application November 21, 1946, Serial No. 711,300

6'Claims.

This invention relates to improvementsin friction driven propellers, pulleys, gears and the like.

The main objects of this invention are:

First, to provide a propeller in which the propeller proper is friction driven so that injury to the blades does not result when the propeller engages an obstruction such as a log or stump or the like.

Second, to provide a friction drive for propellers, pulleys and gears in which the parts may be assembled as a unit to be removably mounted on a driving shaft.

Third, to provide a friction drive including a spring for frictionally urging the clutch elements together, in which the spring is effectively housed and protected and at the same time located for efficient action.

Fourth, to provide a structure embodying the 'aforestated advantages, which may be very ecopeller embodying my invention, the shaft being.

shown in full lines, portions of the support and 1 rudder being indicated by dotted lines.

Fig. 2 is an elevational view of the propeller of the embodiment of Fig. 1 removed from the shaft.

Fig. 3 is a fragmentary view partially in longitudinal section of a slightly modified form. or embodiment of my invention and illustratingan adaptation thereof to a pulley.

Fig. 4 is a. fragmentary view mainly in longitudinal section of a further modification of myinvention, the shaft being omitted.

Fig. 5 is a fragmentary view in longitudinal section of another modification or embodiment of my invention. 1

In the embodiment of my invention illustrated in Figs. 1 and 2, the driving shaft I is provided with a reduced end portion 2 resulting in a rear-v wardly facing shoulder 3.

The rear end of the shaft is threaded as indi-,

cated at 4. The shaft is provided with a clutch member driving pin 5 adjacent the shoulder 3.

The driving clutch member 6 has a conical. peripheral surface 1 and bore 8 removably fitting the shaft. The inner end of the driving clutch member desirably abuts the shoulder 3 and it is provided with a transverse'slot 9 receiving the pin 5 to provide driving engagement with the shaft. The cap nut I0 is threaded into the end of the shaft to clamp the driving clutch member against the shoulder 3 of the shaft and the parts are preferably proportioned so that the nut also clamps the driving clutch member against the pin 5. Where the shaft is not provided with a shoulder the end thrust is entirely sustained by the pin.

The hub I I is internally tapered to receive the bushing I2 which constitutes a friction driven element for the propeller. This bushing is desirably a driving fit within the hub of the propeller so that it constitutes a fixed part thereof. The driving clutch member 6 projects from the rear end of the propeller hub to receive the spring I3, the inner end of which engages the bushing of the hub, the outer end being engaged by the abutment I4 which is threaded upon the threaded end I5 of the driving clutch member. This abutment member I4 is chambered to provide a housing covering and protecting the spring. The abutment member I4 is desirably contoured to complement the external surface I6 of the hub or propeller. The abutment member is desirably knurled as indicated to facilitate grasping. However, it is not commonly necessary to adjust the tension of the Spring after it has been properly adjusted. One of the main advantages of the adjustable abutment is that it avoids the necessity for great care in manufacture; that is, it allows for a wider range of tolerances than would otherwise be permitted.

In Fig. 3 I illustrate an embodiment of my invention in a pulley or gear, a V-belt pulley being shown by full lines and a gear being conventionally included by dotted lines. In this embodiment the hub II engages directly with the driving member 6; that is, the bushing I2 is omitted. In this construction the hub is provided with a rearwardly opening chamber or recess I8 adapted to receive the abutment member I9 which has the outwardly projecting flange 20 supporting the spring 2| corresponding to the spring described. In this construction the spring surrounds the abutment member which is threaded upon the rear end of the driving clutch member.

The embodiment shown in Fig. 4 is the same as that shown in Fig. 3 with the exception that the abutment member 22 corresponding to the abutmeans associated therewith projecting radially outwardly beyond the threaded end of said driving clutch member to constitute an abutment to limit rearward movement of the adjusting member on said driving clutch member.

6. The combination of a driving shaft, a conical rearwardly tapering driving clutch member carried by said shaft and having a reduced portion at its rear end, a propeller provided with a conical driven friction clutch member coacting with said driving clutch member with the driving clutch member projecting rearwardly therefrom, a coiled spring embracing the rearwardly projecting end of said driving clutch member and in thrust engagement with the driven member, and an adjusting member for said spring mounted upon said reduced end portion of said driving clutch member to adjustably support the spring in thrust engagement with the driven clutch member, and a driving clutch member retaining means mounted on said shaft and projecting radially outwardly beyond the rear end of said driving clutch member to constitute a stop to limit rearward movement of said adjusting member on said driving clutch member being closely adjacent to the rear end of the driven member.

MERLE K. BENSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

